212 



MR. A. M. ALTSON ON THE LIFE-HISTORY AND 



The ovipositor, which is extruded, is inserted in diffeient parts 

 of the larva's anatomy. Generally, when the larva is free — i.e., 

 on the surface of the carrion, iindei- it, or on the surface of the 

 soil, — it is inserted about the 1st to 3rd abdominal segments ; very 

 small females attack the cephalic end or the anal plate, particu- 

 larly in the case of full-grown larvfe, probably owing to their 

 inability to get astride the victim, as is usual with the larger 

 females. When the larva is moving in the carrion and the 

 movement is perceptible, the female endeavours to insert the 

 ovipositor through it into any part of the larva, whilst a female 

 coming npon a larva disappearing into the soil or carrion will 

 attack the apex of the abdomen or anal plate, and sometimes is 

 unable to bring the victim to a standstill before the ovipositor 

 has disappeared into the cavity ; whilst, on the other hand, a 

 larva emerging from the carrion is attacked in the anterior 

 region. 



Whilst the insect is ovipositing, the palpi or " feelers " (text- 

 fig. 12), which in I'epose form lateral sheaths to the poison and 



Text-figure 12. 



-Vv'. P 



Palp of ovipositor of 4. wawfZitcfl^or. W.P., wiping-pad. X 61. Original. 



piercing-blades, are constantly in use for locating the moving 

 larva. The ovipositor is withdrawn from a victim with a distinct 

 jerk in order to disengage the barbs of the piercing-blades, and 

 by means of the powerful muscles attached to the hinge-like 

 continuation of the blades, it iiista.nth' spi-ings back between the 

 palpi, the apex of the former aligliting at the base of the latter, 

 so that whilst the sternites are assuming their norma] position of 

 repose, the point of the ovipositor is cleaned by the "wiping-pads " 

 (text-fig. 12, W.P.) of the receding palpi. These "wiping-pads" 

 are on the inside of the basal portion of the palpi, extending 



